Apparatus for emptying reservoirs



Patented Jan. 15, 1952 2,582,753 APPARATUS FOR EMPTYING RESERVOIRSArmand Pierre Herbelleau, Paris, France, assignor to Societe dite:Societe Nationale dEtude ct de Construction dc Moteurs dAviation,Societe Anonyme, Paris, France, a French company Application March 23,1948, Serial No. 16,583 In France March 31, 1947 The present inventionrelates to apparatus for emptying a liquid from a tank.

It is an object of the invention to provide an apparatus which avoidsthe formation of an emulsion such as in known apparatus for emptying aliquid contained in a tank, wherein the suction opening of the emptyingpump is uncovered and this pump sucks in air which mixes with the liquidwhich if the latter is emulsifiable, there is then, formation of anemulsion, which is undesirable.

According to the invention, an apparatus for emptying liquid from a tankcomprises in combination with the tank, a pump for emptying the liquidfrom the tank and means for short-circuiting and connecting together thedelivery side and the suction side of the said emptying pump as soon asthe level of the liquid in the tank sinks below a predetermined level.In such an apparatus, the tank to be emptied is never completelyemptied, and, as a result, the opening of the suction pipe of theemptying pump is always covered with liquid. Thus the emptying pumpnever sucks in air and emulsification is avoided in the emptied liquid.

According to the invention, also in the apparatus a first pipe leadsfrom the bottom of the tank with a pump arranged in said pipe, and asecond pipe branches from the said pipe on the suction side of said pumpand bypasses said pump. A three-way valve device is common to thedelivery side of said pump and the emptying pipe of the apparatus forputting into connection either the delivery side of the pump and theemptying pipe of the apparatus or the delivery side of the pump and theabove said second pipe. Means are also provided for moving the valve ofthe three-way valve device into the position in which it makesconnection between the delivery pipe of the pump and the emptying pipeof the apparatus when the liquid in the tank is above the said mentionedpredetermined level and for moving the said valve in the other positionin which it cuts the said connection and makes simultaneous connectionbetween the delivery pipe of the pump and the above second pipe when theliquid in the tank sinks below the predetermined level.

Numerous apparatus can be constructed in accordance with the principleabove defined and two types of apparatus of this kind are hereindescribed by way of example.

According to one of these types, the three-way valve device includes aslide-valve movable in a cylinder. Said slide valve is subjected on'oneof its faces to they action of a spring and on its opposite face, whenthe level in the tank is above Claims. (Cl. 103-11) a predeterminedlevel, to the high pressure of the liquid of the tank as delivered by anauxiliary pump connected to a suction pipe which opens into the tank atthe above predetermined level.

' A delivery pipe connected to said cylinder. is provided with acalibrated opening and delivers said liquid into the upper part of thetank. When the level of the liquid in the tank has sunk below saidpredetermined level, a low pressure air is delivered by the same pumpand freely escapes into the upper part of the tank through said deliverypipe of the same auxiliary pump.

Numerous apparatus can be constructed in accordance with the principlesabove defined. The diagrammatic drawings appended, given by way ofexample and which do not in any way limit the scope of the presentinvention show, in Figs. 1-4, apparatus of the first form abovedescribed with an auxiliary pump and slide valve.

Fig. 1 is a diagrammatic view of a unit of apparatus of the first form,the plant being in that state of working corresponding to the periodofemptying of the tank.

Fig. 2 is similar to Fig. 1 and shows the same apparatus in that stateof operation corresponding to the working of the emptying pump in shortcircuit with itself.

Fig. 3 shows, on an enlarged scale relative to the preceding figures,the bottom part of the cylinder of the three-way valve device.

Fig. 4 represents, in longitudinal section, one form of the emptyingpump and the additional pump.

In these different figures, the same references denote the same parts.

I is the tank to be emptied, for example, an oil tank and 2 is theemptying pipe connected to the bottom of this tank. Said pipe 2 ispermanentl connected to the suction pipe 3 of the emptying pump 4 of theoil tank and, temporarily,- through a by-pass 5 and a three-way valvedevice to the delivery pipe 6 of said emptying pump 4. The three wayvalve device includes a'cylinder I and a slide valve 8. 9 is theemptying pipe of the tank apparatus which is permanently connected tothe cylinder 1.

I0 is an auxiliary pump which controls the slide-valve 8 in the cylinderI. Said pump It) includes a suction pipe 'H which opens into the tank ata level 12 above that of the lowest point. of said tank and a deliverypipe 13 opening at [4 into one of the bottoms of the cylinder 1. A pipeI6 is permanently connected at one of itsends to the bottom part of thecylinder 1 adjacent to the opening M through a calibrated port 24 and25. A spring 2 suction of the said pump.

- 'side of said pump l7 and at its opposite end, said pipe 16 is open inthe upper part of the tank I to be emptied.

Three ports I9, 20, 2| are arranged sidewise along the cylinder 1 withthe port 19, the port nearest the plane bottom 22 of said cylinder 1opposite to the bottom It, connected to the emptying pipe 9 of theapparatus; the intermediate port 20 is connected to the delivery pipe 6of the emptying pump 4 and the port 2!, the port furthest removedfromrsaid bottom22, is connected to the by-pass 5 for the return to thesuction of the said pump. The bottom part iii of the cylinder 1 isprovided with above mentioned ports l4 and H.

The slide valve 8 is provided with two heads 6 is arranged betweenthe 1and the head 24 and the bottom 22 of cylinder bottom 15 of the same head25 is in front of the cylinder with 23 referring cluded between bothheads 22 and 24.

. The apparatus operates as follows:

(w) As long as the 61 contained in the tank to be emptied covers thesuction orifice l2 of the auxiliary pump I 0, the oil'delivered by thispump exerts its pressure on the head 25 of the slidevalve 8 and pushesit back, compressing the spring'26 carrying the slide-valve '8 into theposition of Fig, 1 where it establishes communication between thedelivery pipe 6 of the'pump 4 and the emptying pipe 9 whereby emptyingis effected.

.(b) When the oil contained in the tank l uncovers the suction orificel2 of the auxiliary pump 10, this pump only sucks in air, which flowsthrough the calibrated orifice H of the delivery pipe IB at a speed muchabove that at which oil from the reservoir previously flowed out throughthe same orifice and brings about a sharp fall in pressure onthe freehead 25 of the slide-valve 8 so that said slide-valve is pressed back byits spring 26 and places itself in the position of Fig.2 where it cutsthe communication between the pipes 9 and 6, and where. it providesatthe' same time a connection between this delivery pipe 6 and the pipe5 of return to the From that time, the evacuating pump 4 functions inthe =circuit 3-43, 6.--20,1'23- -2l, 5--3 thus formed with the quantityof liquid which finds itself int-he bottom part of the tank I below theopening l2 of the suction pipe H of the auxiliary pump 10.

This working ceases as soon asthe'oil conto the section in,-

paratus or the delivery side of said pump and the above mentioned secondpipe and means for moving the valve of said three-way valve device inthe position in which it makes connection between said delivery pipe ofsaid pump and said emptying pipe when the liquid in said tank is above apredetermined level and for moving said valve in the other position inwhich it cuts the said connection and makes connection between thedeliverypipe of said pump and the above mentioned second pipe when theliquid in the tank has sunk below a predetermined level.

2,. Apparatus for .emptying liquid from a tank comprising in combinationa tank, a first pipe leadingfrom the bottom of said tank, a first pumparranged in said pipe, a second pipe branchingfrom said pipe on thesuction side of said pump and Icy-passing said pump, a third pipeleading from the inside of said tank at a predetermined level about thebottom of the same,- an auxiliary pump arranged in said third pipe, anemptying pipe forthe apparatus, a threeway- 'valve device comprising acylinder connected. sidewise with the above mentioned first and tainedin the tank covers again the suction orifice i2 of the auxiliary pump40. V

Preferably, the emptying pump. and the auxiliary pump are driven by acommon pump.

:Ili'ig. 4 showsa common driving shaft 2'! of the. two pump gear wheels28 and 29 respective ing pipefor the apparatus, a three-way valve devicecommon to the delivery side of said first pipe, said second pipe andsaid emptying pipe for putting into connection either the, delivery andemptying pipe of the apsecond pipes and said emptying pipe, a slidevalvearranged in said cylinder, a spring arranged between said slide-valveand one bottom of said cylinder, a delivery pipe connected to saidsecond pump and issuing into the chamber of said cylinder which isopposite to said spring, a calibrated bleed pipe for evacuating in theupper part of'said tank liquid delivered into said chamber :by saidauxiliary pump as long as the level of the liquid in the tank is abovethe upper end of said'third' pipe in said tank, said liquid being thenunder pressure in said chamber of said cylinder and keeping said slidevalve against said spring in the position in which said slide valveconnects said delivery pipe of said first pump with said emptying pipeof the apparatus and said calibrated bleed pipe evacuating afterwardsair delivered bysaid second pump into the same chamber of said cylinderwhen the level of the liquid in the tank sinks below the said upper endof said third pipe with said air then escaping through the calibratedbleed pipe into the upper part of the tank, whereupon the correspondingfall in pressure in said chamber of the cylinder enables the spring tomove the slide valve to cut the connection between the delivery pipe ofthe the emptying pipe of the apparatus and to make connection'betweenthe delivery side of said first pump and the above mentioned secondpipe.

1-3; Apparatus for emptying liquid. from a tank comprising' in combinaon .a tank, a first pipe leading-from the bottom .of said tank,1a first.pump' arranged in said pipe, at second pipe branching from said pipe 0nthe suction sidenf said pump and by-passing said pumpka thirdpipe'leading from the inside of said tank at-a predetermined level abovethe bottom of the same, an auxiliary pump arranged in said third pipe,an emptying pipefor the apparatus, a threeway valve device comprising acylinderconnected sidewi'se with second pipes and said emptying'pipe ofthe'apparatus, .a slide-valve arranged in said cylinder, the saidslide-valve being-provided with a central waisted portion, the depth ofwhich is such that the Y. waisted portion-is adapted to bridge theentrance of said first'mentioned pipe to, and r the entrance of said'emptying pipelfrom, the cylinder at. one end of its travel andtheentrance of both said firstpipe and second by-pass pipes the abovementioned first and r at the other end of its travel, a spring arrangedbetween said slide-valve and one bottom of said cylinder, said thirdpipe connected to said auxiliary pump being connected with the chamberof said cylinder which is opposite to said spring, a calibrated bleedpipe for evacuating into the upper part of the tank liquid delivered insaid chamber by said auxiliary pump as long as the level of the liquidin the tank is above the upper end of said third pipe in said tank, saidliquid being, at that time, under pressure in said chamber of saidcylinder and keeping said slide valve against said spring in theposition in which said slide valve connects said first pipe of saidfirst pump with said emptying pipe of the apparatus and said calibratedbleed pipe evacuating afterwards air delivered by said auxiliary pumpinto the same chamber of said cylinder when the level of the liquid insaid tank sinks below the upper end of said third pipe, said air thenescaping through said calibrated bleed pipe into the upper part of saidtank, whereupon the corresponding fall in pressure in said chamber ofsaid cylinder enables said spring to move said slide valve to cut theconnection between said first pipe of said first pump and said emptyingpipe of the apparatus and to make connection between the delivery sideof said first pump and the above mentioned pipe.

4. Apparatus for emptying liquid from a tank comprising in combination atank, a first pipe leading from the bottom of said tank, a first pumparranged in said pipe, a second pipe branching from said pipe on thesuction side of said pump and by-passing said pump, a third pipe leadingfrom the inside of the tank at a predetermined level above the bottom ofthe same, an auxiliary pump arranged in said third pipe and driven bythe same drive as the first pump, an emptying pipe for the apparatus, a

three-way valve device comprising a cylinder connected sidewise with theabove mentioned first and second pipes and said emptying pipe, aslidevalve arranged in said cylinder, said slide-valve being providedwith a central waisted portion, the depth of which is such that thewaisted portion is adapted to bridge the entrance of said third pipe to,and the entrance of said emptying pipe from said cylinder at one end ofits travel and the entrance of both said first pipe and said secondby-pass pipe at the other end of its travel, a spring arranged betweensaid slide-valve and one bottom of the said cylinder, said third pipe ofsaid second pump issuing in the chamber of said cylinder which isopposite to said spring, a calibrated bleed pipe for evacuating into theupper part of said tank liquid delivered into said chamber by saidauxiliary pump a long as the level of the liquid in the tank is abovethe upper end of said third pipe in said tank, said liquid being, atthat time, under pressure in said chamber of said cylinderv and keepingsaid slide valve against the spring in the position in which said slidevalve connects said first pipe of said first pump with said emptyingpipe of the apparatus and the said calibrated bleed pipe evacuatingafterwards air delivered by said auxiliary pump into the same chamber ofsaid cylinder when the level of the liquid in said tank sinks below theupper end of said third-pipe, said air then escaping through saidcalibrated bleed pipe into the upper part of said tank, whereupon thecorresponding fall in pressure in said chamber of said cylinder enablessaid spring to move said slide valve to cut the connection between saidfirst pipe of said first pump and said emptying pipe of the apparatusand to make connection between said first pipe of said firstpump and theabove mentioned second pipe.

5. Apparatu for emptying liquid from a tank comprising in combination atank, a first pipe leading from the bottom of said tank, a first pumparranged in said pipe, a second pipe branching from said pipe on thesuction side of said pump and by-passing said pump, a third pipe leadingfrom the inside of said tank at a predetermined level above the bottomof the same, an auxiliary pump arranged in said third pipe and driven bythe same drive as said first pump, an emptying pipe for the apparatus, athree-way valve device comprising a cylinder connected sidewise with theabove first and second pipes and said emptying pipe, a slidevalvearranged in said cylinder, said slide-valve being provided with acentral waisted portion, the depth of which is such that the waistedportion is adapted to bridge the entrance of said first mentioned pipeto, and the entrance of said emptying pipe from, said cylinder at oneend of its travel and the entrance of said first pipe and said secondby-pass pipe at the other end of its travel, a spring arranged betweensaid slidevalve and one bottom of the said cylinder and said third pipeof said second pump issuing in the chamber of said cylinder which isopposite to said spring, a calibrated bleed pipe for evacuating into theupper part of said tank liquid delivered in said chamber by saidauxiliary pump as long as the level of the liquid in the tank is abovethe upper end of said third pipe in said tank, said liquid being, atthat time, under pressure in said chamber of said cylinder and keepingsaid slide valve against said spring in the position in which said slidevalve connects said first pipe of said first pump with said emptyingpipe of the apparatus and said calibrated bleed pipe evacuatingafterwards air delivered by said auxiliary pump into the same chamber ofsaid cylinder when the level of the liquid in the said tank sinks untilthe said upper end of said third pipe, said air then escaping throughsaid calibrated bleed pipe into the upper part of said tank, whereuponthe corresponding fall in pressure in said chamber of said cylinderenables said spring to move said slide valve to cut the connectionbetween said first pipe of said first pump and said emptying pipe of theapparatus and to make connection between the delivery side of said firstpump and the above mentioned second pipe, and the body of both pumps andthe cylinder of said slide valve forming a unitary block.

ARMAND PIERRE HERBELLEAU.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 28,307 Sanderson et al. May 15,1860 683,630 Westinghouse Oct. 1, 1901 1,699,194 Junkus Jan. 15, 19292,354,693 Martin Aug. 1, 1944

